In the operation of a typical agricultural combine that employs a threshing rotor, the flow of crop residue, sometimes referred to as material other than grain (MOG), remaining after threshing is typically discharged into a crop residue treatment and distribution system for treatment thereby and for ultimate distribution onto or over a field. Straw and residue chopper assemblies and residue spreader assemblies of various types and constructions have long been in use in or with such residue treatment and distribution systems. Such assemblies have operated to chop or pulverize the crop residue resulting from a harvesting operation into finer pieces and/or to spread the resulting crop residue, whether chopped into finer pieces by operation of a chopper assembly or passed to the spreader assembly as larger pieces of residue, onto and over the field. Such chopper and residue spreader assemblies have taken various forms, depending upon the desires of users and manufacturers.
Many typical harvesters have traditionally employed technology and methods that have become associated with what is sometimes referred to as a hood mount chopper. Generally, such hood mount choppers can be described as flail choppers, and the systems of which they are a part have evolved to the point that they may include over 100 flail knives on a rotating chopper, mounted within a dedicated housing that provides an appropriate environment for the operation of the rotating chopper so as to best maximize its performance. The rotating chopper of such a residue management system may often operate at or above 3000 RPM and provide suitable and sufficient energy to the chopped material to be able to effect a spread of the chopped material over a width of up to 40 feet, which width generally corresponds to the cut width of the header. Such a residue management system is thus operable for its intended purpose of chopping and spreading the chopped material over a field, and generally operates effectively in such regard. With such a system, if a user does not desire to chop the straw, he may turn the chopper off and bypass, or route the material flow around, the chopper.
Typical Case IH harvesters, however, have, for over 25 years now, in an effort to provide greater equipment versatility while reducing equipment complexities, typically employed a somewhat different technology in the residue management systems thereof. Such alternative technology, the primary purpose of which has been the transport of material away from the threshing system, has utilized a multifaceted construction that affords greater versatility in the transport of such material in that such material can not only be transported, but can also be treated in varying manners dependent upon the desires of operators. Such constructions have come to be known as integral choppers or integral chopper or chopping systems due to the integration of a chopping function, in addition to the primary transport function, into the combine and its operations. Such integral chopper systems, because of their positioning within the combine and their functional capabilities, offer a versatility not generally available with the hood mounted chopper systems.
Such integral chopper systems have been so designed that, as noted hereinabove, their primary function is the transport of material away from the threshing system and a secondary function is the treatment of such material as it is being so transported. Such operations are usually effected in one of two different ways. Most commonly, the integral chopper system is operated to transport the material from the threshing system to a spreading system as a rotary chopper element or portion rotates at or near 3000 RPM so as to quickly move the material rearwardly and to also chop it into smaller pieces as it is being so transported. Less commonly, the integral chopper system is operated to more gently transport the material from the threshing system to a spreading system as the rotary chopper element operates at a much slower speed, typically at only about 800 RPM, with considerably less chopping activity. In the former instance, the desire and expectation is that the material will be transported and that the shortest mean length of cut will be realized to allow for modern minimum tillage applications while the chopping is accomplished using as little power as possible. In the latter instance, the desire and expectation is that the material will be transported in such a manner as to provide the longest and least damaged straw possible.
Such integral chopper systems, which are based upon a legacy design utilized by Case IH harvesters for approximately 25 years, have recognized advantages over hood mounted chopper systems in that they often allow combines to be manufactured with simpler designs and fewer moving parts, resulting in less expensive base units and lighter weight products, while typically performing at levels competitive to performance standards of hood mounted choppers. Despite the recognized versatility and advantages of the integral chopper systems, attempts to improve such systems have continued, fueled in part by customer and critiques and demands, including beliefs expressed by some users that the chop quality realizable by integral chopper systems, at least in length of cut (LOC), has remained inferior to the chop quality that could be realized by hood mounted choppers, as well as stated desires by users for integral chopper systems that can better absorb impacts with foreign objects without significant damage or breakage.
In light of these and other concerns raised by users, and to address various European marketing demands, attempts have been made in more recent years to develop new types of integral chopper systems, including integral chopper systems that could utilize flail-type elements and connectors instead of fixed and rigidly mounted knife blades on the rotary element. In general, such integral chopper systems have met with limited success, due in part to difficulties in dealing with the increase in material throughput that has been experienced over the past 10 years as machine capacities, and consequent demands upon the integral position, have increased.
More particularly, at least with respect to flail-type integral chopper systems, it has proven difficult to achieve a system that can, to the desired degrees, effectively offer and provide the dual capabilities of, in one alternative, chopping into or reducing the residue to finer pieces for spreading as such residue is transported rearwardly and, in the other alternative, more gently transporting the residue, in larger pieces, rearwardly for windrowing. The use of flail-type elements and mountings in lieu of fixed and rigidly mounted knife blades on the rotary element has generally not resulted in the degree of success and satisfaction desired therefore, especially when such an integral chopper system has been operated as an 800 RPM flail chopper. In such operation, the flail-type elements, due to the lack of inertia associated therewith, have sometimes, even in the absence of heavy loading, folded back along their direction of travel and caused plugging of the harvester and consequent reliability problems. Such factor has been seen as a significant limitation to, and disadvantage of, a flail-type integral chopper as opposed to a fixed blade integral chopper.
On the other hand, such flail-type integral choppers offered one significant advantage over fixed blade integral choppers in that they could, unlike fixed blade integral choppers, better absorb energy when foreign objects, such as auger fingers or rocks, were encountered within the crop residue flow during operations. Often, with a fixed blade integral chopper, an impact with such a foreign object, especially if relatively severe, would effect mission disabling damage to a fixed blade integral chopper system, such as by cracking or breaking either or both the rotating knife blades or the stationary counter knife elements, or even snapping off the knife blade or element or breaking off its mounting, resulting in missing knife blade components and denigrating the performance of the assembly. With the flail-type integral choppers, however, the rotating flail-type elements could fold back if and when a foreign object became captured by the stationary knife elements, thereby significantly minimizing the possibility of damage to or breakage of the stationary knife elements or the rotating flail-type elements.
Consequently, attempts to develop improvements to these systems have continued. The ongoing challenge has been to develop a chopper assembly that can offer the advantages desired while overcoming or minimizing the disadvantages that have been encountered with prior art systems. These chopper system improvements, as discussed and described hereinafter, are newly developed and employ various inventive concepts to realize in great part the various advantages sought therefore while overcoming and/or minimizing the difficulties and disadvantages associated with the prior art constructions.